Nowhere in the sales literature does iboats or Seasense mention that their lights do not correctly fit this base. The Seasense lights and poles require a different locking base. In addition, this base has non-standard mounting holes. If this is a replacement, you will need to drill new holes in your boat. Caution - do not order the Seasense poles or light with this base. As for me, I won't be buying this brand any more.